One of the complaints that consumers have regarding the brushing of teeth is the difficulty in washing away the residue of toothpaste and water left from a brushing and over time the ability to maintain a clean toothbrush. Part of the problem in washing away this residue is that the bristle carrier has been either a solid piece of plastic with blind holes or a solid piece of plastic in which bristles have either been embedded through a fusion process or through a molding process. In any case, it is quite likely that some of this residue will continue to reside on the bristle carrier around the bristles or bristle tufts as surface tension between the residue, and the material of the bristle carrier will cause residue to linger on the surface despite the user's best efforts.
U.S. Pat. No. 5,836,036 discloses a self-cleaning toothbrush wherein the head is provided with a series of intersecting support rails defining a grid pattern having the same thickness as the peripheral portion of the head. Open areas are created in the grid pattern which are overall greater than the corresponding bristle bunches to enhance the cleaning action when the head is placed under running tap water. The head including the grid pattern is of uniform thickness.
U.S. Pat. No. 6,088,870 shows a toothbrush with flexibly mounted bristles in a lattice or open network disposed against an otherwise imperforate base portion of the head. Thus, the head does not have through holes.
It would be desirable to provide a toothbrush which overcomes the problems relating to being able to maintain the toothbrush clean.
It would also be desirable if techniques could be used for effectively mounting the bristles to the carrier or head.
Various techniques have been disclosed in the prior art utilizing laser radiation and other techniques in the manufacture of toothbrushes. U.S. Pat. Nos. 4,592,594 and 4,762,373, for example, disclose rounding the bristle tips by the action of laser radiation. U.S. Pat. No. 5,306,143 discloses incorporating a laser device in the handle and a lens in the head as part of an optical system. Other patents disclosing various heat application techniques and related technology are U.S. Pat. Nos. 4,132,449, 4,390,384, 4,869,277, 4,979,782, 5,052,419, 5,390,984, 5,044,041, 5,143,425, 5,407,254, 5,472,263 and 5,673,454. In addition, reference is made to PCT/EP97/00825 (WO 97/30611), EP0124937 and EP0150785.